1.cause表示造成某一事实或现象的直接原因或起因(后常接of)：Drunken driving is often the cause of accidents.酒醉开车往往酿成事故。 2.reason常用于说明或解释某种行为或看法的理由(后接for或不定式)：You have no reason/cause for complaint/to complain.你没有理由抱怨。 3.excuse常指借口、辩解(后常接of)。 4.reason之后可接why引导的定语从句：The reason why the boss doesnt trust him is that he has often lied.老板不信任他的原因是因为他时常说谎。Drunken driving is often the of accidents. cause-Have they found out the _ of the fire? -Yes. It was a cigarette end that _ the fire.A. cause; caused B. reason; caused C. cause; cause D. reason; cause-Im sorry I stepped outside for a smoke. I was very tired. -There is no _for this while you are on duty.A. reason B. excuse C. cause D. chance2002上海According to the recent research, heavy coffee drinking and heart attack is not necessarily and effect.A. reason B. impact C. fact D. cause